Manila - Two people were killed and eight injured when unidentified gunmen strafed a passenger bus in the southern Philippines, a military spokesman said Thursday.

The bus was travelling Wednesday along the highway in Gutalac town in Zamboanga del Norte province, 735 kilometres south of Manila, when the gunmen opened fire at it.

Major Ramon David Hontiveros, a regional military spokesman, said authorities were investigating the possibility that the attackers mistook the bus for their intended target.

Hontiveros said no suspects have been identified, but Muslim separatist rebels and Islamic militants operate in the province. (dpa)